Modular Navigable Probe

ABSTRACT

A navigable probe system and method of use is provided. The system may include a handle assembly having a locking mechanism enclosed and a stylus, a cannula, and a tracking device extending from the handle assembly. The stylus may include undercuts for receiving pins of the locking mechanism. A cam of the handle assembly may rotate such that in a first position, the pins of the locking mechanism may be engaged with the undercuts and in a second position, the pins of the locking mechanism may be disengaged from the undercuts releasing the stylus from the locking mechanism. The stylus may be slidably engaged with an inner diameter of the cannula. In some arrangements, the handle assembly may include a quick connect system that in a first position attaches the cannula to the handle assembly and in a second position releases the handle assembly and thus stylus from the cannula.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of U.S. patent application Ser.No. 15/847,225, filed Dec. 19, 2017, which is a continuation of U.S.patent application Ser. No. 14/196,514 filed Mar. 4, 2014, now U.S. Pat.No. 9,877,786, which claims the benefit of the filing date of U.S.Provisional Application No. 61/773,375 filed Mar. 6, 2013, thedisclosures of which are hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to systems and methods for pedicle screwinsertion into a spine, and in particular, to navigational probes forcreating a trajectory in a pedicle for subsequent pedicle screwinsertion.

Various systems have been developed to aid surgeons in translating andtracking the position of surgical tools or probes during surgicalprocedures, such as the system described in U.S. Pat. No. 7,166,114(“the '114 patent”), the entire disclosure of which is herebyincorporated by reference herein. Such systems have been useful inperforming neurological related procedures such as procedures forinsertion of pedicle screw into the spines of patients. A navigablejamshidi and certain custom probe designs have been used to perform suchsteps of these procedures. However, these devices frequently losepositions registered by the navigation tracking system that interfaceswith the devices, often due to unreliable attachment of an adapterconnecting the navigation tracking system to the devices which leads toundesirable rotational movement of the navigation tracking system. Assuch, these probe devices require calibration of both position andorientation with respect to the tracking systems with which they areused. Furthermore, custom probe designs often have a stylus tip that isdifficult to remove from bone upon insertion and, moreover, jamshidishave a relatively small cannula diameter which makes them prone topermanent bending and lodging in the bone when used with navigable probedevices.

Other systems having navigable disposable needles that may be used withdedicated, often permanently attached tracking systems and those havingrigid cannulated probes or jamshidis, require separate instruments toperform various steps of surgical procedures in which these systems areused. For instance, such systems may require a slim dilator to initiateuniform expansion of an incision prior to using another larger dilator.When calibrating a navigable probe device having either an adapter forattaching or when permanently attaching a navigation tracking system toa probe, separate calibration of additional navigable instruments isrequired to be used during the surgical procedure.

Thus, there is a need for a navigable probe that can be used to performmultiple surgical steps and that is modular to allow for separation of ahandle from any of a stylus and a cannula. There is a further need for anavigable probe having a fixed portion relative to a tracking systemused therewith which maintains the registry after replacement of one orboth of the stylus and cannula without the need to recalibrate in orderto prevent unreliable registry of probe positions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a navigable probe assembly in accordancewith an embodiment.

FIG. 2 is a partial exploded and partial perspective view of a portionof the navigable probe assembly of FIG. 1.

FIG. 3 is a perspective view of an upper cap assembly of the navigableprobe assembly of FIG. 1.

FIGS. 4(A) and 4(B) are perspective views of arrangements of assembliesof styli and cannulae for use with a navigable probe assembly inaccordance with certain embodiments.

FIG. 5 is a plan view of the navigable probe assembly of FIG. 1 in whichthe upper cap assembly has been removed.

FIG. 6 is a cross-sectional front side view of a portion of thenavigable probe assembly of FIG. 1.

FIG. 7 is a cross-sectional rear side view of another portion of thenavigable probe assembly of FIG. 1.

FIG. 8 is a perspective view of a handle assembly and a tracker arm ofthe navigable probe assembly of FIG. 1.

FIG. 9 is a side view of a navigable probe assembly in accordance withanother embodiment.

FIG. 10 is a cross-sectional side view of a portion of the navigableprobe assembly of FIG. 9.

FIG. 11 is another perspective view of the navigable probe assembly ofFIG. 1.

FIG. 12 is another partial exploded and partial perspective view of aportion of the navigable probe assembly of FIG. 1.

FIG. 13 is another perspective view of an upper cap assembly of thenavigable probe assembly of FIG. 1.

FIGS. 14(A) and 14(B) are perspective views of the stylus and cannulafor use with the navigable probe assembly of FIG. 1.

FIG. 15 is another plan view of the navigable probe assembly of FIG. 1in which the upper cap assembly has been removed.

FIG. 16 is another cross-sectional front side view of a portion of thenavigable probe assembly of FIG. 1.

FIG. 17 is another cross-sectional rear side view of another portion ofthe navigable probe assembly of FIG. 1.

FIG. 18 is another perspective view of a handle assembly and a trackerarm of the navigable probe assembly of FIG. 1.

DETAILED DESCRIPTION

Where reference is made herein to directional terms such as “proximal,”“proximal most,” “distal,” and “distal most,” it is to be understoodthat “proximal” and “proximal most” refer to locations closer to a useror operator of the device or method being described and that “distal”and “distal most” refer to locations further from a user or operator ofthe device or method being described.

Referring to FIG. 1, a navigable probe assembly 10 according to oneembodiment may include a handle assembly 20 attached to a tracker arm100 as well as a stylus 60 concentrically inserted into a cannula 70. Aportion of each of the stylus 60 and cannula 70 may be disposed withinthe handle assembly 20. As shown, a tracking module 150 may be attachedto a connector extending from the tracker arm 100.

As illustrated in FIG. 2, the handle assembly 20 includes an upper capassembly 21, a handle base assembly 30 (described further below), alocking mechanism 50, and a lower handle 40 that in conjunction with theupper cap assembly 21 enclose a portion of the handle base assembly 30and the locking mechanism 50. As shown in FIG. 3, a cam 23 may beinserted into a cavity 22 of the upper cap assembly 21 (as best shown inFIG. 6) and fixed to the upper cap assembly 21. As shown, in somearrangements, the cam 23 is fixed by a screw to the upper cap assembly21. In other arrangements (not shown), the cam 23 may be fixed to theupper cap assembly 21 by, but not limited to, bonding the cam 23 to theupper cap assembly 21 using an adhesive, such as epoxy, or by formingthe cam 23 and the upper cap assembly 21 as a unitary body, such as bynet-shape injection molding or by cutting of a solid block.

The upper cap assembly 21 may include at least two tabs 24 extendingfrom opposing positions around an inner perimeter 25 of the upper capassembly 21 as well as a flat lower surface 26. The lower handle 40 mayinclude at least two recesses 42 within a boss 45 extending from a flatupper surface 46 of the lower handle 40 and having a boss undercut 47(as best shown in FIG. 6) around a perimeter of the boss 45. Therecesses 42 may be located at positions around the boss 45 correspondingto the positions of the tabs 24. Thus, there may be at least as manyrecesses 42 as there are tabs 24 formed in such a configuration. Thetabs 24 of the upper cap assembly 21 may be inserted into the recesses42 of the lower handle 40, and the upper cap assembly 21 and the lowerhandle 40 may be rotated relatively to one another as the tabs 24 slidewithin and around the boss undercut 47. In some arrangements (notshown), the tabs and the boss may be reversed such that the tabs may beattached to the lower handle and the boss may extend from the upper capassembly.

The upper cap assembly 21 and the lower handle 40 may have correspondingshapes such that upon their relative rotation, the upper cap assembly 21and the lower handle 40 may be locked together, and the flat lowersurface 26 of the upper cap assembly 21 and the flat upper surface 46 ofthe lower handle 40 may rest flush against each other around respectiveperimeters of these surfaces. The ability to engage and disengage theupper cap assembly 21 and the lower handle 40 may allow for cleaningdebris out of an interior of the handle assembly 20. In somearrangements, such as shown in FIG. 2, the upper cap assembly 21 and thelower handle 40 may have smooth and rounded exteriors that provide for amore ergonomic surface for handling by a user of the navigable probeassembly 10. As shown, the upper cap assembly 21 and the lower handle 40may have a hard or rigid shell that allows for the reuse thereof insubsequent surgical procedures.

As shown in FIGS. 4A and 4B, the stylus 60 includes a proximal end 62having a stylus undercut 64 for connection with the handle base assembly30 on a first portion of the proximal end 62, as discussed further downbelow, and a protrusion 66 for connection with a proximal end 72 of thecannula 70. The stylus 60 further includes a distal end 68 having anouter diameter sized to pass through an inner diameter of the cannula 70and having a sharp tip that acts in a similar manner to a trochar, suchas known by those of ordinary skill in the art. As further shown in FIG.4A, the proximal end 72 of the cannula 70 may have a recess 76 forreceiving the protrusion 66 of the stylus 60. Stylus flats 65 andcannula flats 75 may be formed on the respective proximal ends 62, 72 ofthe respective stylus 60 and cannula 70 for aiding in alignment withflats on the tracker arm 100, as described further below. These flatsaid in preventing rotation of the stylus 60 and the cannula 70 to allowfor easier insertion of these components into bone.

As further shown in FIG. 4A, in some arrangements, depth markings 77 maybe included on a distal end 80 of the cannula 70. Also, in somearrangements as shown, the cannula 70 may include grooves 71 along acentral portion of the cannula 70 to provide a hand grip to ease theassembly and disassembly of the probe assembly 10 and to allow thecannula to be pulled out of bone, such as a pedicle, in instances inwhich the cannula is not lodged in the bone. As further shown in FIG.4B, in some arrangements, a dielectric coating 78 may be added to thedistal end 80 of the cannula 70 which may be used when the cannula 70 isused as part of a neuromonitoring procedure known to those of ordinaryskill in the art. As shown in FIGS. 4A and 4B, in some arrangements, amore proximal portion of the distal end 80 of the cannula 70 may have alarger diameter than a distal most portion 82 of the cannula 70, whichmay be tapered, such that the cannula 70 may act as a dilator of thesoft tissue in place of an initial dilator traditionally used fordilating the soft tissue in a separate step of the procedure. In somearrangements, the cannula 70 may include a tapered tip 84 that may serveas a jamshidi to further facilitate insertion of the cannula 70 intobone and to maximize the stiffness at the distal end of the probeassembly 10.

As illustrated in FIGS. 5 and 6, the locking mechanism 50 includes abase 51, pins 52, impaction cap 53, and resilient element 54. The pins52 may be inserted on an outer end through holes 55 within protrudingstands 56 on opposite sides of the base 51 and on an inner end throughholes 58 extending radially through the impaction cap 53. The base 51may be inserted into a cavity 48 of the lower handle 40. As illustrated,in some arrangements, the resilient element 54 may be a leaf spring thatmay be U-shaped. The resilient element 54 may be compressed between pinflanges 57 extending radially from a longitudinal axis of the pins 52.In an alternative arrangement (not shown), the resilient element may bea set of at least two coiled springs in which each of the coiled springsis compressed between the impaction cap 53 and the pin flanges 57.Although the base 51, the impaction cap 53, and the lower handle 40 areshown as separate components to allow easier access to clean thesecomponents, combinations of the base and the impaction cap, the base andthe lower handle, as well as all of the base, the impaction cap, and thelower handle may be integrated such that any of these combinations ofthese structures may form a monolithic structure.

As illustrated in FIGS. 6 and 7, the handle base assembly 30 may beinserted into a distal portion of the lower handle 40. As shown, thehandle base assembly 30 may include an inner tube 32 that extends from adistal end of the impaction cap 53 as well as an outer tube 33 and aquick connect system 90 that each surround and are coaxial with theinner tube 32. As shown in FIG. 7, the quick connect system 90 includesa collar 91 that surrounds the outer diameter of the inner tube 32 andthat, when assembled, axially compresses a compression element 92, suchas a compression spring, and radially compresses a locking element (orelements) 93, such as but not limited to balls or other objects withprotruding features, to maintain an axial position of an object, such asthe cannula 70 as described further herein, in contact with the lockingelement 93. To release the cannula 70, the collar 91 may be pushedaxially to cause the compression element 92 that otherwise maintains theaxial position of the collar 91 to be compressed against an end of theouter tube 33. As further shown in FIG. 7, the collar 91 has an innerdiameter 94 around a circumference thereof that tapers in a directionaway from the compression element 92 such that, upon axial movement ofthe collar 91 causing the compression element 92 to be compressed, thelocking element 93 relaxes the compression force against the cannula 70.Upon relaxation of the compression force, the cannula 70 may then bedisplaced axially, and subsequently removed from an interconnection withanother element, such as the inner tube 32 of the handle base assembly30.

As best shown in FIG. 6, the stylus 60 may be placed within and theproximal portion 62 thereof may be slidingly engaged with an innerdiameter of the impaction cap 53 and an inner diameter of the inner tube32 of the handle base assembly 30. As shown in FIGS. 6 and 7, when thedistal end 68 of the stylus 60 is placed within the cannula 70, asdescribed previously herein, the stylus 60 may be slidingly engaged withthe inner diameter of the cannula 70. In this configuration, the outerdiameter of the cannula 70 may be slidingly engaged with a portion ofthe inner tube 32 of the handle base assembly 30 that is distal to theportion of the inner tube 32 to which the stylus 60 is slidinglyengaged.

Referring to FIG. 7, the inner tube 32 may include internal flats 34 ona proximal end thereof which mate to and engage with each of therespective stylus flats 65 and cannula 75 to prevent rotation of thestylus 60 and the cannula 70 at least when the stylus 60 and the cannula70 are fully inserted in the inner tube 32. In this manner, torque maybe transmitted through the navigable probe assembly, such as by asurgeon's hand, through the handle assembly to the cannula and thestylus during manipulation within bone. Moreover, preventing rotation ofthe stylus and cannula allows for setting of the position of the stylus60 relative to the locking mechanism 50, and thus for the setting of therelative angular position of the stylus undercuts 64 to the pins 52 asdescribed previously herein.

As illustrated in FIG. 8, the impaction cap 53 extends through the uppercap assembly 21 such that a proximal surface of the impaction cap 53 isexposed to a user. As shown, the impaction cap 53 is not fixed to theupper cap assembly 21 such that the upper cap assembly 21 may be rotatedrelative to the impaction cap 53 and lower handle 40. In this manner, anarrow 110 on the proximal surface of the impaction cap 53 may indicatewhen the upper cap assembly 21, and thus the cam 23, are positioned suchthat the pins 52 are within the stylus undercuts 64 and thus in a“locked position” or, in contrast, when the positions of thesecomponents are such that the pins 52 are not within the stylus undercuts64 and thus in an “unlocked position”. As shown, the impaction cap 53may include an aperture 61 along a longitudinal axis of the cap. Theaperture may permit insertion of instruments or portions of instrumentstherethrough, such as those described further herein.

As shown in FIGS. 1, 2, and 7, the tracker arm 100 may be attached onone end thereof to the inner tube 32 and extend radially and upwardlyfrom the point of attachment. Such an attachment may be by aninterference fit between an outer diameter of the inner tube 32 and aninner diameter of a circumferential flange on the attachment end of thearm 100, or by other well-known means of attachment. The tracker arm 100may include opposing flats 101 that lie in planes parallel to the stylusand cannula flats 65, 75. In this manner, the stylus 60 and cannula 70may be inserted into the inner tube 32 of the handle base assembly 30 ina predetermined orientation relative to the opposing flats 101 of thetracker arm 100 and such that the stylus undercut 64 is in alignmentwith the pins 52.

The tracker arm 100 may include a striking plate 102 on a distal surfacethereof. Such a plate may be a flat region stamped into the arm 100 thatprovides a greater surface area than the rest of the arm 100 along thedistal portion of the arm with which to strike the arm and provide animpaction force in a proximal direction for use in separating thecannula from the other components of the navigable probe assembly 10,especially when the cannula is inserted into bone.

On an end of the tracker arm 100 may be one or more posts 105 forconnection with a tracking module, such as the tracking module 150 shownin FIG. 1 or the tracking module 250 shown in FIG. 9.

Referring to the configuration of FIGS. 5 and 6, in operation, when thecam 23 is rotated clockwise, an inner diameter of the cam along thelongitudinal axes of the pins 52 of the locking mechanism 50 becomesincreasingly smaller until the cam contacts the pins 52 to cause thepins 52 to slide in the direction of the longitudinal axes until thepins 52 are within or engaged with the respective stylus undercuts 64and are thus in the locked position, as discussed previously herein. Incontrast, when the cam 23 of the upper cap assembly 21 is rotated in thecounterclockwise direction, the resilient element 54 may provide a forceradially against the pin flanges 57 such that the pins 52 may beretracted to a position in which the pins 52 are not within or engagedwith the stylus undercuts 64 and are thus in the unlocked position.

Referring to FIG. 7, in operation, the quick connect system 90 may bereleased by applying an axial force in the proximal direction, which maybe applied by a user to collar flanges 96, to remove the radial loadapplied against cannula 70. As the cannula 70 is not fixed to the stylus60, when quick connect system 90 is released and the locking mechanismis in the locked position, the stylus 60 may be slidingly separated fromthe cannula 70. In this manner, the handle assembly 20 engaged with thestylus 60 through the locking mechanism 50 (along with the tracker arm100) may also be separated from the cannula 70. The stylus 60 may beseparated from the locking mechanism 50, and thus the handle assembly20, by placing the locking mechanism 50 in the unlocked position. Inthis manner, one stylus may be exchanged for a new or different stylus.

Still referring to FIG. 7, the impaction cap 53 of the locking mechanism50 may have a physical hard stop 59 such that upon placement of thehandle assembly 20 and locking mechanism 50 onto the stylus 60, theproximal most end of the stylus 60 abuts the physical hard stop 59 toset the relative position of the stylus 60 to the locking mechanism 50,and thus the relative axial position of the stylus undercuts 64 to thepins 52 and at least the tip at the stylus distal end 68 to the hardstop 59. An outer diameter of the stylus 60 may be substantially thesame as a mating inner diameter of the inner tube 32 or the cannula 70to set the relative radial position and orientation of the stylus 60 tothe respective inner tube 32 or cannula 70. In this manner, a preciseand repeatable position of the stylus with respect to a navigationtracking system, such as the tracker module 150 (as shown in FIG. 1),may be established.

The inner tube 32 of the handle base assembly 30 may have a physicalhard stop 36 such that, upon placement of the handle assembly 20 ontothe cannula 70, a step 73 (as best shown in FIG. 4B) located at theproximal end 72 of, or in the alternative the proximal most end of, thecannula abuts the physical hard stop 36 to set either or both of anengagement length of the handle base assembly 30, including the quickconnect system 90, with the cannula 70 and the relative axial positionof at least the tip 84 at the cannula distal most end 82 to the hardstop 36. An outer diameter of the cannula 70 may be substantially thesame as a mating inner diameter of the inner tube 32 to set the relativeradial position and orientation of the cannula 70 to the inner tube 32.In this manner, a precise and repeatable position of the cannula withrespect to a navigation tracking system, such as the tracking module 150(as shown in FIG. 1), also may be established. Due to the use of thephysical hard stops 36 and 59, upon complete assembly of the navigableprobe 10, a user may strike the impaction cap 53 to facilitate insertionof the stylus 60 and cannula 70 into bone.

FIGS. 9 and 10 illustrate an alternative arrangement of a navigableprobe 210. As shown, the navigable probe 210 may include a handleassembly 220, stylus 260, cannula 270, and tracker arm 300 havingtracking posts 205 connected with the tracking module 150. As furthershown, in some arrangements of the navigable probe 210, the handleassembly 220 may not include a locking mechanism therein. Instead, asshown in FIG. 10, a proximal end 262 of the stylus 260 as well asproximal end 272 of the cannula 270 may be inserted into a cavity of acollar 291 that is part of a quick connect system 290 (not fully shown)at a distal end of the handle assembly 220. In this manner, the stylus260 and the cannula 270 may be separated from the handle assembly 220when the quick connect system 290 is released but may be fixed, or atleast non-rotational, with respect to the handle assembly 220 when thequick connect system 290 is engaged with, i.e. compressed against, thecannula 270. Distal ends 268, 278 of the stylus 260 and cannula 270 mayhave similar configurations to the distal ends 68, 78 of the stylus 60and cannula 70 of the navigable probe 10.

Referring again to FIG. 9, an end of the tracker arm 300 may be set at apoint P0 that is along a radius drawn from a point P2 set at theproximal most end of the navigable probe 210. Moreover, the distal mostpoint of the navigable probe 210, identified as point P1, may be set ata nominal distance of 7 inches, which is preferably in a range between 5inches and 9 inches, from the distal most end of the collar 291 of thequick connect system 290. In this manner, the relative distances of thepoints P0, P1, and P2 remain fixed such that the tracking module 150 canrepeatably and reliably detect the position and orientation of thenavigable probe assembly 10 due to the fixed relative positions of thecomponents of the assembly 10.

In use, in accordance with an embodiment, a cannula 70 of a navigableprobe assembly 10 may be inserted through the skin of a patient. Thecannula 70 may have a larger diameter through most of the distal end 80and act as a dilator as it enters through the skin of the patient. Afterpassing the cannula 70 through the skin a predetermined depth at apredetermined orientation as determined by a calibrated tracking module150 extending from the navigable probe assembly, as described in the'114 patent, which may be a depth determined prior to or during asurgery, a distal end 68 of a stylus 60 located within the tapereddistal end 82 of the cannula 70 of the navigable probe assembly 10 maybe inserted into the spine or other bone of a patient. In general, auser may strike a proximal surface of an impaction cap 53 exposed on aproximal end of a handle assembly 20 in order to supply the necessaryforce to insert. A rounded, ergonomic shape of the handle assembly 20 ofthe navigable probe assembly 10 may provide a smooth surface on which topress the navigable probe assembly 10 through the skin and into thespine of the patient.

Prior to or during insertion of the navigable probe assembly 10, theupper cap assembly 21 of the probe assembly 10 may be rotated to a“locked position” to cause a cam 23 that may be located within thehandle assembly 20 to rotate a corresponding angle of rotation. The cam23 may have a varying diameter such that, upon rotation of the upper capassembly 21 to the locked position, a diameter of the cam 23 that isrelatively smaller than the rest of the cam 23 causes pins 52 of alocking mechanism 50 to move toward the center of the cam 23 and becomeengaged with the stylus 60 of the probe assembly 10.

Due to the engagement of the respective flats 65, 75 of the stylus 60and the cannula 70 with the respective portions of the respective flats34 of the inner tube 32 of the handle assembly 20, rotation of thehandle assembly 20 may transmit a corresponding angular rotation to thestylus 60 and the cannula 70 such that a rotation of the handle assembly20 by the user has a corresponding rotation of the stylus 60 and thecannula 70, allowing the user to control the angular movement of thestylus 60 and the cannula 70. As the distal end 68 of the stylus 60 mayhave a tapered blade thereon, and the cannula 70 may have cutting flutesor other non-cylindrical features (not shown), such control of thestylus 60 and the cannula 70 can enhance the ability of the user of thenavigable probe assembly 10 to cut through bone.

After the stylus 60 and the cannula 70 are embedded into the body to apredetermined depth, in some arrangements, a user may disengage thestylus 60 and the other components of the probe assembly 10 from thecannula 70 when the upper cap assembly 21 of the probe assembly 10 is in“locked position” by releasing the quick connect system 90 and bypulling the probe assembly 10 with the stylus 60 engaged thereto suchthat the stylus 60 may slide axially in the proximal direction throughthe inner diameter of the cannula 70. In this manner, the cannula 70alone may remain in the bone. In such a configuration, a K-Wire (notshown) may be inserted into the inner diameter of the cannula 70 andfurther may be advanced into the bone to mark the cannula and stylustrajectory and to serve as a guide for subsequent steps in theprocedure.

After the stylus 60 and the cannula 70 are embedded into the body to apredetermined depth, or the stylus 60 and the probe assembly 10 aredisengaged from the cannula 70, a user may rotate the upper cap assembly21 to an “unlocked” position to cause the cam 23 to rotate acorresponding angle of rotation. Upon such rotation, the diameter of thecam 23 that is relatively larger than the rest of cam 23 may provide aspace for the pins 52 to move outwardly from the center of the cam 23.One or more springs of the locking mechanism 50 may be compressedagainst pin flanges 57 on the pins 52 such that as the cam 23 rotates toprovide a space for the pins 52 to move, the one or more springs pushthe pins 52 outwardly from the center of the cam 23 such that the pins52 remain against the changing diameter of the cam 23. As the pins 52reach a predetermined radial position from the center of the cam 23 asthey move outwardly from the center of the cam 23, the pins 52 maydisengage from undercuts 64 of the stylus 60. In this manner, when thepins 52 become disengaged from the stylus 60, the stylus 60 may beremoved from the navigable probe assembly 10 in the absence of otherrestrictions, such as constriction in some arrangements that may becaused by a quick connect system, as described further herein. Theability to disengage the cannula 70 and the stylus 60 from the probeassembly 10 provides an option to leave the stylus 60 inside the cannula70 while embedded in the bone, allowing for one or both ofintra-operative fluoroscopy images to be produced and photos to be takenalong the longitudinal axis of the cannula 70 without interference fromthe probe assembly 10. Subsequently, the probe assembly 10 may bereattached to the cannula 70, and also may be reattached to the stylus60, to continue the procedure.

In some arrangements in which the cannula 70 is connected to a handlebase assembly 30 of a handle assembly 20 by a quick connect system, suchas the quick connect system 90, the quick connect system 90 may beoperated by sliding a collar 91 axially to release the cannula 70 whichmay then be separated from the handle assembly 20. In some arrangements,such separation of the cannula 70 may allow a second dilator having aninner diameter larger than the outer diameter of the original dilator tobe slid over the original dilator, whether with or without the stylus 60or K-wire inserted, without assistance from the navigation trackingsystem. The option of sliding the larger diameter dilator over thecannula 70 and the stylus 60 is possible due to the fact that the shapesof the exteriors of both the cannula 70 and the stylus 60 are bound by apredetermined outer diameter that is smaller than an inner diameter ofthe larger dilator. Due to the larger diameter of the second dilator,the user may further enlarge or dilate the incision produced by theoriginal cannula. By serving the function of the initial dilator, thecannula 70 may save a surgical step of removing the cannula 70 andreplacing the cannula 70 with the initial dilator.

In the example of navigated probe assembly 10, when the pins 52 aredisengaged from the stylus 60, removal of the cannula 70 may permit thestylus 60 to also be removed from the handle assembly 20. After removingthe stylus, the user may later reinsert one or both of the originalstylus 60 and the cannula 70 or may replace one or both of the originalstylus 60 and the cannula 70 with one of both of a second stylus and asecond cannula, respectively. The tracking module 150 may then berecalibrated with one or both of the second stylus and the secondcannula such that the tracking module 150 can repeatably and reliablydetect the position and orientation of the navigable probe assembly 10with one or both of the second stylus and the second cannula inserted.Moreover, through control of precise dimensions of the stylus andcannula during manufacturing thereof, the original calibrationparameters of the tracking module 150 may remain valid and therecalibration step may be avoided.

In some arrangements (not shown), with the stylus removed from thehandle assembly, an instrument or portion of an instrument, such as butnot limited to a drill bit, a needle for one or both of aspirating boneand delivering bone cement, a neuromonitoring probe, and an ultrasoundprobe (including but not limited to a Doppler type of the ultrasoundprobe) may be inserted and removed through the aperture 61 in theimpaction cap 53 and the inner tube 32 of the handle assembly 20, and insome arrangements, further through the cannula 70. Additionally, in somearrangements (not shown) with the stylus inserted in the handleassembly, a neuromonitoring cable or a neuromonitoring connected may bepassed through the aperture of the impaction cap and connected to thestylus. Additionally, in other arrangements (not shown), with the stylus60 and the cannula 70 removed, an instrument or a portion of aninstrument, such as but not limited to a drill guide, a probe or aneedle-specific cannula, an awl, end plate preparation instruments andinterbody device insertion instruments can be inserted through thedistal end of the probe assembly. In some arrangements, theseinstruments may be configured to be engaged with one or both of thelocking mechanism 50 and the quick connect system 90.

It is to be understood that the disclosure set forth herein includes allpossible combinations of such particular features. For example, where aparticular feature is disclosed in the context of a particular aspect,arrangement, configuration, or embodiment, or a particular claim, thatfeature can also be used, to the extent possible, in combination withand/or in the context of other particular aspects, arrangements,configurations, and embodiments of the invention, and in the inventiongenerally.

Furthermore, although the invention herein has been described withreference to particular embodiments, it is to be understood that theseembodiments are merely illustrative of the principles and applicationsof the present invention. It is therefore to be understood that numerousmodifications may be made to the illustrative embodiments and that otherarrangements may be devised without departing from the spirit and scopeof the present invention as defined by the appended claims.

1. (canceled)
 2. (canceled)
 3. A method for replacing components of amodular navigable probe assembly comprising the steps of: rotating afirst subassembly of a handle assembly relative to a second subassemblyof the handle assembly from a first position in which the stylus islocked to the handle assembly to a second position in which the stylusis removable from the handle assembly; and moving a collar of a quickconnect system along a portion of the handle assembly from a firstposition in which the cannula is locked to the handle assembly to asecond position in which the cannula is removable from the secondsubassembly.
 4. The method of claim 3, further comprising sliding atleast a portion of the stylus through the cannula.
 5. The method ofclaim 3, further comprising removing the handle assembly from both thestylus and the cannula when both the first subassembly of the handleassembly is rotated to the second position of the first subassembly andthe collar of the quick connect system is moved to the second positionof the collar.
 6. The method of claim 3, further comprising, afterremoval of at least one of the stylus and the cannula, receiving in thehandle assembly a drill guide, a drill, an awl, a neuromonitoring probe,an ultrasound probe, a bone aspiration and cement delivery needle, aprobe-specific cannula, a needle-specific cannula, end plate preparationinstruments, or interbody device insertion instruments.
 7. The method ofclaim 3, further comprising inserting pins of a locking mechanismattached to the second subassembly into a proximal end of the stylussuch that a resilient element changes between relaxed and compressedstates.
 8. The method of claim 7, further comprising, during rotation ofthe first subassembly to the first position of the first subassembly,rotating a cam of the first subassembly to supply a force against atleast a portion of the pins such that the pins are inserted into theproximal end of the stylus and thereby fix the stylus in positionrelative to the handle assembly.
 9. The method of claim 7, furthercomprising, during rotation of the first subassembly to the secondposition of the first subassembly, retracting the pins from the stylusby a force supplied by the resilient element.
 10. The method of claim 9,further comprising, removing the handle assembly and the stylus from thecannula.
 11. A surgical method, comprising: rotating a first subassemblyof a handle assembly relative to a second subassembly of the handleassembly from a first position in which a stylus is removable from thehandle assembly to a second position in which the stylus is locked tothe handle assembly, wherein the handle assembly is part of a navigableprobe assembly; inserting a cannula of the navigable probe assembly intoa body to a predetermined depth at a predetermined orientation, whereinthe depth and orientation are provided by a calibrated tracking moduleof the navigable probe assembly spaced from the cannula; and insertingthe stylus through the cannula and into the body.
 12. The method ofclaim 11, wherein the stylus inserting step further comprises striking aproximal surface of an impaction cap on a proximal end of the handleassembly.
 13. The method of claim 11, further comprising replacing thestylus and the cannula with a second stylus and a second cannula in thenavigable probe assembly; and recalibrating the tracking module with thesecond stylus and the second cannula such that the calibrated trackingmodule repeatably and reliably detects the position and orientation ofthe navigable probe assembly with the second stylus and the secondcannula inserted.
 14. The method of claim 11, further comprisingreplacing the stylus and the cannula with a second stylus and a secondcannula in the navigable probe assembly such that the tracking modulerepeatably and reliably detects the position and orientation of thenavigable assembly with the second stylus and the second cannulainserted.
 15. The method of claim 11, further comprising rotating thehandle assembly to transmit a corresponding angular rotation to thestylus and the cannula to cut a bone of the body.
 16. The method ofclaim 11, further comprising rotating the handle assembly to therebyrotate a tapered blade of the stylus to cut a bone of the body.
 17. Themethod of claim 11, further comprising rotating the handle assembly tothereby rotate one or more cutting flutes of the cannula to cut a boneof the body.
 18. The method of claim 11, further comprising insertingpins of a locking mechanism attached to the second subassembly into aproximal end of the stylus and a resilient element.
 19. The method ofclaim 18, further comprising, during rotation of the first subassemblyto the first position of the first subassembly, rotating a cam of thefirst subassembly to supply a force against at least a portion of thepins such that the pins are inserted into the proximal end of the stylusand thereby fix the stylus in position relative to the handle assembly.20. The method of claim 18, further comprising, during rotation of thefirst subassembly to the second position of the first subassembly,retracting the pins from the stylus by a force supplied by the resilientelement.
 21. The method of claim 20, wherein the retracting stepincludes altering a resilient element between a compressed state and arelaxed state.
 22. The method of claim 20, further comprising, afterrotating the first subassembly of the handle assembly to the firstposition, removing the handle assembly and the stylus from the cannulasuch that the cannula remains inserted into the bone.
 23. The method ofclaim 22, further comprising: dilating soft tissue of the body to afirst diameter with the cannula; sliding a dilator over the cannula; andfurther dilating the soft tissue of the body with the dilator to asecond diameter larger than the first diameter.